Downloads used to be shown in a completely separate window, which
could be toggled using the keyboard shortcut Cmd-Option-L. In
Lion, they appear in a popover panel attached to the toolbar of
whatever browser window you happen to be using. Unfortunately,
there is no keyboard shortcut to toggle the appearance of this
popover.

Using FastScripts and a simple UI Scripting script, I was able to
restore this functionality, so that Safari on Lion toggles the
appearance using the old familiar Cmd-Opt-L shortcut.